Tsunami warning cancelled after magnitude-7.9 earthquake off Alaska

Tsunami warnings have been cancelled after a magnitude-7.9 earthquake hit the Gulf of Alaska in the early hours of Tuesday.

Officials at the National Tsunami Centre cancelled the warning after a few tense hours when waves failed to show up in coastal Alaska communities.

Alaska’s Division of Homeland Security and Emergency Management said there have been no reports of damage, so far.

Mickey Varnadao, a computer specialist with the warning centre in Palmer, Alaska, said early on Tuesday that an advisory remains in effect for parts of Alaska, from Kodiak Island to Prince William Sound.

Watches were cancelled for Washington, Oregon, California and Hawaii.

Earlier, tsunami warnings for parts of Alaska and Canada and a tsunami watch for the entire US west coast were issued.

A tsunami watch was also issued for Hawaii but was later cancelled.

Officials in Japan also said there was no tsunami threat there.

The quake, initially measured at magnitude-8.2, hit 256 kilometres south-east of Chiniak, Alaska at a depth of 25km at 0931 GMT, the US Geological Survey said.

“If you are located in this coastal area, move inland to higher ground. Tsunami warnings mean that a tsunami with significant inundation is possible or is already occurring,” Anchorage Office of Emergency Management said in a warning for Alaska and British Columbia.

“Based on all available data a tsunami may have been generated by this earthquake that could be destructive on coastal areas even far from the epicentre,” the Pacific Tsunami Warning Centre said.

A map showing travel times of a possible tsunami caused by an earthquake near Alaska. Photo: Twitter: NWS Tsunami Alerts

Police in Kodiak, an island in the gulf of Alaska, warned residents to get at least 30.5 metres above sea level.

In a video posted to their Facebook page, an officer told residents that while Pillar Mountain was safe, it was full and could not be accessed within five or 10 minutes. The officer instead directed residents to the local high school car park.

Japan’s meteorological agency said it was monitoring the situation but did not issue a tsunami alert.

One Kodiak resident tweeted a video in which the tsunami sirens can be heard and wrote that hearing the sound at 1:00am on a Tuesday was “terrifying”.

tsunami sirens going off in kodiak after the earthquake, i usually only ever hear the weekly siren test at 2pm on wednesdays so hearing it at 1am on tuesday is actually terrifying!! pic.twitter.com/ea5y7U6xnf